Cam and cam follower assemblies are commonly used in duplicating apparatus wherein the shape of the cam determines the final shape of work pieces. An example of such apparatus is the piston turning machine shown in co-pending application Ser. No. 389,483 filed Aug. 20, 1973, now U.S. Pat. No. 3,869,947, and owned by the assignee of this application. Operation of machinery of this general type is plagued by the problem of wear of the cam follower adversely affecting the accuracy of the machine and necessitating frequent changes of the follower. This tendency of the follower to wear is due in part to the fact that the cam follower is always moving and is subject to heavy loading in order to maintain it in engagement with the cam. In the past, attempts have been made to prolong the life of the follower by forming it of a variety of different materials such as metal carbide, plastic fibers, graphite impregnated formica, bronze and stainless steel. All of these materials are satisfactory but they do not meet the objective of a long service life. The object of the present invention, therefore, is to provide an improved apparatus which includes a cam follower constructed so that it can be maintained over a prolonged service life without wear.